P. Intasqui

Differences in the seminal plasma proteome are associated with oxidative stress levels in men with normal semen parameters

OBJECTIVE To study the seminal plasma proteome in association with semen lipid peroxidation levels in men with normal semen parameters. DESIGN Cross-sectional study. SETTING University andrology and research laboratories. PATIENT(S) A total of 156 normozoospermic men. INTERVENTION(S) Seminal lipid peroxidation levels were assessed in individual samples through thiobarbituric acid reactive substances quantification. Subsequently, lipid peroxidation data were used to divide the samples into the experimental groups: low lipid peroxidation levels (control group, bottom 15%, n = 23) and high lipid peroxidation levels (study group, top 15%, n = 23). Seminal plasma proteins from these groups were pooled (four pools per group, with biological variation between the pools) and used for a shotgun proteomic analysis using a liquid chromatography-tandem mass spectrometry approach. Quantitative data were used for univariate (unpaired Students t test) and multivariate (partial least-squares discriminant analysis, logistic regression, and discriminant analyses) statistical analyses. Significant proteins were also used for functional enrichment analysis. MAIN OUTCOME MEASURE(S) Seminal plasma protein profile and postgenomic pathways of seminal plasma are associated with seminal lipid peroxidation levels. RESULT(S) In total, 629 proteins were quantified in seminal plasma. Of these, 23 proteins were absent or underexpressed and 71 were exclusive or overexpressed in the study group. The main enriched functions in association with seminal lipid peroxidation were unsaturated fatty acids biosynthesis, oxidants and antioxidants activity, cellular response to heat stress, and immune response. Moreover, we suggested mucin-5B as a potential biomarker of semen oxidative stress. CONCLUSION(S) The seminal plasma proteome does reflect semen lipid peroxidation status and, thus, oxidative stress.

Unraveling the sperm proteome and post-genomic pathways associated with sperm nuclear DNA fragmentation

PurposeSperm DNA fragmentation has been suggested as a marker for infertility diagnosis and prognosis. Hence, understanding its impact on male physiology and post-genomic pathways would be clinically important. We performed the proteomics and functional enrichment analyses of viable spermatozoa from ejaculates with low and high sperm DNA fragmentation to identify protein expression and pathways altered in association with sperm DNA fragmentation.MethodsSperm DNA fragmentation using the Comet assay and the Komet 6.0.1 software was assessed in raw samples from 89 subjects from a human reproduction service. The Low and High sperm DNA fragmentation groups were formed according to the Olive Tail Moment variable. Spermatozoa proteins from these groups were pooled and analyzed by a shotgun proteomic approach (2D nanoUPLC-ESI-MSE). Differentially expressed proteins were used for a functional enrichment study.ResultsTwo hundred and fifty-seven proteins were identified or quantified in sperm from the Low and High sperm DNA fragmentation groups. Of these, seventy-one proteins were exclusively or overexpressed in the Low group, whereas twenty-three proteins were exclusively or overexpressed in the High group. One hundred and sixty-three proteins were conserved between these groups. We also functionally related the differentially expressed proteins in viable spermatozoa from the groups. Processes such as triacylglycerol metabolism, energy production, protein folding, response to unfolded proteins, and cellular detoxification were found to be altered in these cells.ConclusionsSperm DNA fragmentation is associated with differential protein expression in viable spermatozoa. These proteins may potentially be used as biomarkers for sperm DNA integrity.

Analysis of the functional aspects and seminal plasma proteomic profile of sperm from smokers

To evaluate the effect of smoking on sperm functional quality and seminal plasma proteomic profile.

Sperm nuclear DNA fragmentation rate is associated with differential protein expression and enriched functions in human seminal plasma.

To analyse the proteomic profile of seminal plasma with the aim of identifying the proteins and post‐genomic pathways associated with sperm DNA fragmentation.

Association between the seminal plasma proteome and sperm functional traits

OBJECTIVE To analyze the seminal plasma proteome and biological functions associated with sperm functional alterations. DESIGN Cross-sectional study. SETTING University andrology and research laboratories. PATIENT(S) A total of 156 normozoospermic men. INTERVENTION(S) Sperm mitochondrial activity, acrosome integrity, and DNA fragmentation were evaluated in a semen aliquot. Remaining semen was centrifuged, and seminal plasma was utilized for proteomic analysis (liquid chromatography-tandem mass spectrometry). Patients were divided into percentiles (15%) to form the following groups: substudy 1, high (control, n = 26) and low (study, n = 23) sperm mitochondrial activity; substudy 2, high (control, n = 23) and low (study, n = 22) sperm acrosome integrity; and substudy 3, low (control, n = 22) and high (study, n = 22) sperm DNA fragmentation. Groups were compared using univariate and multivariate analyses. Differentially expressed proteins were used for functional enrichment analysis. MAIN OUTCOME MEASURE(S) Seminal plasma proteome and postgenomic pathways are associated with several sperm functional traits. RESULT(S) In total, 506, 493, and 464 proteins were observed in substudies 1, 2, and 3, respectively. Enriched functions in substudy 1 were intramolecular oxidoreductase activity, aminoglycans catabolism, endopeptidases inhibition, lysosomes, and acute-phase response (study group). In substudy 2, main enriched functions were phospholipase inhibition, arachidonic acid metabolism, exocytosis, regulation of acute inflammation, response to hydrogen peroxide, and lysosomal transport (study group). In substudy 3, enriched functions were prostaglandin biosynthesis and fatty acid binding (study group). We proposed eight, six, and eight seminal biomarkers for substudies 1, 2, and 3, respectively. CONCLUSION(S) Seminal plasma proteome reflects sperm mitochondrial activity reduction, acrosome damage, and DNA fragmentation, with several postgenomic functions related to these alterations.

Prostate cancer proteomics: clinically useful protein biomarkers and future perspectives

ABSTRACT Introduction: Although prostate cancer constitutes one of the most important, death-related diseases in the male population, there is still a need for identification of sensitive biomarkers that could precociously detect the disease and differentiate aggressive from indolent cancers, in order to decrease overtreatment. Proteomics research has improved understanding on mechanisms underlying tumorigenesis, cancer cells migration and invasion potential, and castration resistance. This review has focused on proteomic studies of prostate cancer published in the recent years, with a special emphasis on determination of biomarkers for cancer progression and diagnosis. Areas covered: Shotgun and targeted-proteomic studies of prostate cancer in different matrices are reviewed, i.e., prostate tissue, prostate cell lines, blood (serum and plasma), urine, seminal plasma, and exosomes. The most important biomarkers for cancer diagnosis and aggressiveness characterization are highlighted. Expert commentary: In general, results demonstrate alteration in cell cycle control, DNA repair, proteasomal degradation, and metabolic activity. However, these studies suffer from low reproducibility due to heterogeneity of the cancer itself, as well as to techniques utilized for protein identification/quantification. Downstream confirmatory studies in separate cohorts are warranted in order to demonstrate accuracy of these results.

Cysteine-rich secretory protein 3: inflammation role in adult varicocoele

Cysteine‐rich secretory protein (CRISP‐3), a protein involved in inflammatory response, is highly increased in seminal plasma of adolescents with varicocoele and altered semen analysis, but not in adolescents with varicocoele and normal semen. It is not known, however, whether this increased seminal concentration occurs as an acute marker during the initial stages of varicocoele or whether this persists as an altered protein pathway.

Understanding the seminal plasma proteome and its role in male fertility

Seminal plasma is a complex fluid comprised of secretions from the seminal vesicles, the prostate, bulbourethral glands and from the seminiferous tubule lumen / epididymides / vasa deferentia. While it has been established that seminal plasma serves not only as a medium to carry, protect, and nourish sperm after ejaculation up to fertilization, but also as a functional modulator of sperm function, there is still a need to properly characterize the molecular make-up of seminal plasma in fertile men, and to understand how this is altered in different causes of male infertility. The main purpose of this manuscript was to review articles that studied the human seminal plasma proteome, ranging from characterizing a fertile seminal plasma proteomic map to studies comparing seminal plasma from fertile and infertile men, and comparing seminal plasma of fertile or normozoospermic men to a diverse range of biological causes for male infertility. Finally, this review has focused on the association between semen and sperm functional quality and the seminal plasma proteome, in order to demonstrate cellular and molecular mechanisms of male infertility. Due to the untargeted nature of the majority of the studies presented in this review, and to the diverse range of techniques utilized to study the seminal plasma proteomic composition, many differentially expressed proteins were observed. However, in general, it seems that there is a seminal plasma proteome associated to male fertility, and that different biological conditions or cellular phenotypes shift its pathways away from its homeostatic condition to altered energy production pathways. Moreover, it seems there is an inflammatory component to the seminal plasma of infertile men. In conclusion, there are a number of studies focused on the proteomic composition of human seminal plasma; downstream confirmatory studies will help to understand specific pathways of infertility in different biological conditions.RésuméLe plasma séminal est un liquide complexe comprenant les sécrétions des vésicules séminales, de la prostate, des glandes bulbo-urétrales, et des sécrétions provenant de la lumière des tubes séminifères/épididymes/canaux déférents. Bien qu’il a été établi que le plasma séminal n’est pas seulement un milieu servant à transporter, protéger et nourrir les spermatozoïdes après l’éjaculation et jusqu’à la fécondation, mais qu’il constitue aussi un modulateur fonctionnel des fonctions spermatiques, il demeure nécessaire de caractiser de manière appropriée la constitution moléculaire du plasma séminal des hommes féconds, et de comprendre comment celle-ci est altérée dans les différentes causes d’infertilité masculine.Le principal objectif de cet article est de passer en revue les études du protéome du plasma séminal, en allant de celles ayant caractérisé une carte protéomique du plasma séminal fertile aux études ayant comparé le plasma séminal d’hommes féconds et inféconds et à celles ayant comparé le plasma séminal d’hommes féconds ou normozoospermiques à celui d’hommes présentant diverses causes d’infertilité. Pour finir, la présente revue est centrée sur l’association entre d’une part la qualité fonctionnelle du sperme et des spermatozoïdes et d’autre part le protéome du plasma séminal dans le but de démontrer les mécanismes cellulaires et moléculaires de l’infertilité masculine. En raison de la nature non ciblée de la majorité des études présentées dans cette revue, et de la grande diversité des techniques utilisées pour étudier la composition protéomique du plasma séminal, de nombreuses protéines différentiellement exprimées ont été observées.Cependant, d’une façon globale, il semblerait qu’il y ait un protéome séminal associé à la fertilité masculine et que des situations biologiques ou des phénotypes cellulaires particuliers l’éloignerait de son point d’équilibre vers des états associés à une production énergétique altérée. De plus, il semblerait exister une composante inflammatoire du plasma séminal chez les hommes infertiles. En conclusion, il existe de nombreuses études centrées sur la composition protéomique du plasma séminal humain; de futures études de confirmation seront utiles à la compréhension des voies spécifiques de l’infertilité dans ses différentes conditions biologiques.